The present invention relates to a method of removing carbon from the exhaust gases of an internal combustion, especially a Diesel engine, including conveying the exhaust gases through the filter means of a carbon filter to remove the carbon, and burning the removed carbon during operation of the engine utilizing electrical energy that is introduced via an appropriate electrode arrangement. The present invention also relates to an apparatus for carrying out such a method.
One heretofore known method makes use of the electrical conductivity of the collected carbon (U.S. Pat. No. 4,829,766 issued May 16, 1989, to Dietmar Henkel, the applicant of the present application). With this known method, via a suitably shaped electrode pair which is in electrical contact with the carbon layer, an electrical voltage is impressed the result of which is a flow of current that serves to heat up the carbon to the ignition temperature. As a consequence of the negative temperature coefficient of the specific electrical resistance of the carbon, the electrical energy exchange at that location is locally inhomogeneously effected, i.e. the burn-out occurs in a slowly wandering, hot, linear zone. In order to obtain a large, active burn-out surface for the purpose of achieving a high burn-out rate, this known method requires several electrode pairs accompanied by simultaneous boundary regulation of the individual streams or a rapid switch-over of the hot stream to the individual electrode systems.
It is therefore an object of the present invention to achieve a more homogeneous current flow and hence a greater (more rapid) carbon burn-out without great complexity.